Homes created under permitted development rights (PDR) conversions offer worse residential environments than those converted under normal planning permission, research for the Government has found.
Many PDR schemes avoided making any planning gain contribution despite creating increased costs for local authorities, the research also found.
Researchers from the Bartlett School of Planning, at University College London, said in Research into the Quality Standard of Homes Delivered Through Change of Use Permitted Development Rights that PDR homes “do seem to create worse quality residential environments than planning permission conversions in relation to a number of factors widely linked to the health, wellbeing and quality of life of future occupiers”.
Researchers visited 639 building in the council areas of Bristol, Crawley, Derby, Enfield, Huntingdonshire, Manchester, Richmond, Sandwell, Sunderland, Wakefield and Waverley.
They found PDR homes tended to have smaller windows - or in rare cases no windows - compared with those with planning permission and those in commercial and industrial areas often offered “extremely poor residential amenity”.
Some 72% of PDR homes had only single aspect windows, compared with 29.5% of homes with planning permission.
PDRs allow for changes of use without full planning permission and in 2013 were extended to allow buildings such as offices, light industrial and retail premises to be converted to residential.
Internal design also revealed significant differences, with only 22.1% of PDR homes meeting the nationally described space standards - compared to 73.4% of those with full planning permission - with some having just 16 square metres of space.
Far more PDR homes were studios or one bedroom flats, at 68.9% of compared with 44.1% of those with planning permission.
Researchers found that developers of many PDR homes had avoided making any planning contributions, because they were not liable for Section 106 obligations and frequently could avoid the community infrastructure levy since they created no additional floorspace.
The report said: ”This concerns many local planning authorities, given that additional residential units does create additional pressure on local infrastructure particularly social infrastructure but also potentially green infrastructure, given the lack of amenity space provision in so many schemes.”
Higher design standards might lead to fewer units overall particularly in locations with the most marginal development viability, but this was hard to quantify as “many developers seem unwilling to discuss the viability of change of use schemes, however a balance must clearly be sought between quality and quantity”.
The Local Government Association has called for permitted development rights to be removed.
Cllr David Renard, LGA housing and planning spokesman, said: “This independent report rightly backs our long-standing concerns over the detrimental impact on local communities of rules allowing home conversions without planning permission. It provides further evidence on why it is more vital than ever that planning should remain local.
“Under these rules, communities have no way to ensure developers build high-quality affordable homes in the right places, provide any affordable homes as part of the development, along with infrastructure that provides enough schools, promotes greener and more active travel, and tackles climate change."
He added: “Developers must no longer be allowed to bypass the planning system and local communities must be able to have a say on all new developments in their area.
“It is vital that councils and local communities have a voice in the planning process and are able to oversee all local developments so councils can deliver resilient, prosperous places that meet the needs of their communities.”